1. Field of the Invention
The invention relates to an electrical line for motor vehicles which has at least two insulated electrical conductors which are combined to form one unit and, when the line is completely fitted, to which a sensor is connected at one end of said line.
2. Description of Related Art
“Lines of this type which are fitted with sensors are used in modern motor vehicles —called “vehicles” for short in the text which follows —in large, continuously increasing numbers for monitoring and display purposes. A “vehicle” may be both a passenger car and a heavy goods vehicle or a trailer. Sensors can be used to monitor and display, for example, the temperature at different points of a vehicle, the anti-lock braking system (ABS), the electronic braking system (EBS), the wear on brake shoes or the tire pressure. Sensors in the form of ultrasonic transducers are also used to measure the distance of a vehicle from an obstacle and to trigger a warning signal. All of these sensors are connected to a central unit, which is present in the respective vehicle, via an electrical line. ”
Appropriate lines can be combined together with other lines to form a cable harness from which said lines protrude with different lengths. After the cable harness is laid, the lines have to be conducted to the site of use of the respective sensor with an appropriate length and in the process be fastened to the vehicle body or other fixed points of a vehicle. DE 103 10 050 A1 discloses a cable harness of this type, in which a number of insulated electrical conductors is arranged in a plastic corrugated tube. When the corrugated tube is slit, the conductors can be inserted into it. The conductors are drawn into a corrugated tube which is not cut. In order to fasten the corrugated tube and therefore the cable harness, clamps are used which are pressed against the corrugated tube and fixed to a substrate by means of a locking clip or a machine screw.
DE 100 58 204 A1 also discloses a cable harness in which a number of insulated electrical conductors are surrounded by an outer jacket comprising foamed material. A stepped sealing element which likewise comprises foamed material is fitted to one end of the outer jacket, it being possible for said sealing element to be inserted into a passage opening in a metal vehicle body panel. The outer jacket and the sealing element can be produced together in a standard foaming process.
The need for fastening to the vehicle body or other fixed points of a vehicle also applies, particularly, for lines which are laid, for example, individually from the central unit to the site of use of the sensor. In this case, appropriate fixed points are located not only within the body of a vehicle but, for example, also outside on the floor of said vehicle or in wheel arches. The lines have to be designed to be robust and sufficiently mechanically stable for all sites of use. In order to protect the conductors, they have, for example, a common jacket comprising insulating material which surrounds said conductors. They are generally fastened at fixed points in the vehicle—as disclosed in DE 103 10 050 A1—using additional fastening elements, it also being possible for parts of a fastening device to also be mounted on the outside of the line beforehand, these parts interacting with corresponding parts which are present at the fixed points.